Sean Ellis/Capital Press
Onions are planted in a field in Meridian, Idaho, March 24. Onion growers in Idaho and Oregon will once again be able to use Starane Ultra, an herbicide that has proven helpful in controlling volunteer potatoes and weeds such as kochia.

ONTARIO, Ore. — Oregon and Idaho dry bulb onion growers will again be able to use a herbicide that has proven effective in controlling volunteer potatoes and certain broadleaf weeds such as kochia.

The Environmental Protection Agency label for use of Starane Ultra in dry bulb onion fields in this region had expired at the end of 2013.

The EPA has revised the expiration date for its use in Oregon to Dec. 31, 2018.

The expiration date for the herbicide’s use in Idaho onion fields is Dec. 31, 2014. A similar request from Washington state to extend the label’s expiration date is pending.

The Idaho-Oregon onion growing region is the nation’s largest in terms of total volume and kochia is a problem for many growers here, said Stuart Reitz, an Oregon State University cropping system Extension agent in Malheur County.

Starane “is something that a lot of onion growers in this area use for … controlling weeds,” he said.

Reitz said the herbicide is used in all of the onion producing areas in the Pacific Northwest and has had a special local needs label for use in Idaho, Oregon and Washington.

Although growers were pretty sure the label would be extended, they weren’t positive, he said.

“It took a little longer than people had hoped for,” said Reitz, who fielded several calls from growers in recent weeks wanting to know if the label had been extended.

Reitz said the chemical has proven successful in controlling kochia, one of the more common weeds onion growers in the region have to deal with.

A summer annual, kochia can also be a host for the iris yellow spot virus, one of the top disease concerns for onion growers.

Reitz said Starane isn’t as widely used as some other herbicides such as Roundup, “but it’s a good tool for growers to have in their tool box. It’s another herbicide that growers can use to help manage the overall weed situation in their crops.”

Reid Saito, who grows onions and other crops in Nyssa, Ore., said Starane is also good for controlling volunteer potatoes.

“If you have potatoes in your rotation, it’s a really good herbicide for controlling volunteer potatoes,” he said. “If they come up in an onion field, they are really hard to control.”